In today's wireless networks that are designed to operate with a frequency reuse factor of one, such as HSPA (High Speed Packet Access) and LTE (Long Term Evolution), inter-cell interference is relatively high, particularly for users located near the cell edge but also at the base station level. One solution to this problem consists in providing advanced wireless reception techniques to mitigate multi-cell interference and increase the cell edge throughput. Such techniques mainly exploit the interference that exists between cells, rather than seeing them as problematic. For instance, at the base station level, it has been proposed to perform signal processing across multiple cells in a coordinated or cooperative fashion so as to enhance the received signal quality as well as decrease the received spatial interference, thus leading to a higher capacity per cell and, more importantly, an increased and homogeneous quality of service across cells. Namely, with these techniques such as uplink coordinated multipoint reception (CoMP), base station antennas are connected together through a high capacity backhaul network (e.g. via optical fiber links) so that data can be exchanged between them, then the multiple antenna RF (Radio Frequency) signals are processed jointly in order to better detect users that interfere with each other. This means, that operations such as equalization are jointly performed for the multiple antenna RF signals. Joint equalization may also be used in architectures such as C-RAN (cloud radio access network) or HetNet (Heterogeneous networks), where the equalization is jointly performed in a centralized processing based on multiple antenna RF signals originating from a plurality of remote radio units.
However, conventional equalizers which may be used in such scenarios are usually designed for equalizing signals originating from a predetermined number of antennas. Indeed, in today's field, most of available conventional equalizers are specifically designed to equalize signals originating solely from one, two, four or eight antennas. In such cases, conventional equalizers are not able to optimally operate in view of unsupported antenna configurations, such as three, five, six or seven antennas, which, however, are very likely to occur where techniques such as CoMP are employed or in C-RAN and HetNet, for instance.
Therefore, it would be desirable to have an improved equalizer that would be able to perform equalization under unsupported antenna configurations.